Method of and machine for making pulp rovings



y 1933- M. o. SCHUR ET AL METHOD OF AND MACHINE FOR MAKING PULP ROVINGS Filed June 6, 1931 Patented May 23, 1933 UNITED STATES PATENT oFrrcE MILTON O. SCHUR AND WILLIAK B. EEGLITZ, OFIBERIIIN, NEW HAMPSHIRE, ASSIGNORS TO BROWN GOMPANY, OF BERLIN, NEW HAMPSHIRE, A CORPORATION OF MAINE METHOD 0] AND MACHINE FOR MAKING PULP ROVINGS Application filed June a, 1931. Serial No. 542,649:

This invention relates to the manufactureof pulp rovings, for instance from wood pulp, being more especially concerned with an improved method of and machine for -making pulp rovings of uniformity, high strength, and other desirable characteristics at high speeds.

g It has heretofore been proposed to produce rovings from short-fibered material, such as wood pulp, by depositing the pul as ribbons on a wire screen or cloth, and t en furling the ribbons in damp condition by means of angularly-arranged belts into round form. Aside from the fact that the rigging necessary for mounting and adjusting the belts is cumbersome and expensive, it is diflicult to secure uniform rovings of bad quality, particularly at high speeds, w ere there is danger of effecting incomplete or no furling of the ribbons and/or of causin snarls or entanglements between the close y spaced pulp deposits. In addition to these defects, the belts are troublesome, because of buckling, twisting, and other distortions, particularly when wide belts are used, such as are essential for large scale production.

We have found that the furling ofvthe pulp ribbons may be accomplished on the very wire cloth on which they have been deposited by the simple expedient of engaging their edge portions by a friction roll and rolling them out at an angle to the direction of travel of the wire, the roll being-caused to rotate by the wire, if desired. The periphery of the friction roll may be surfaced with any suitable material, but we prefer to use a roll of the same general type as the so-called dandy roll used in paper manufacture. This type of roll is covered with wire cloth of relatively fine mesh, and serves to accomplish the desired function of furling or rolling the ribbons mostadmirably when they are in the proper state of dam ness. Inasmuch as there is a tendency for fibers in the pulp ribbons to become. entangled with the wire on which they are deposited and thus to stick to the wire, we prefer to lift only their edge portions to be first engaged by the furlingroll soas to ensure a furlin or rolling action. We do not, however, herein claim this feature as our invention, as this is fully disclosed and claimed in application Serial No. 542,648,

filed June 6, 1931, by Frederick W. Vogel and \Villiam B. Meglitz.

. We also prefer to dry the roll surface after it has peripherally moved out of furling position so as to obviate any tendency of the rovings to stick to the furling roll, which,v

by contact with the damp pulp ribbons becomes inoist. It is thus seen that not only have we effected a simplification in the method and in the machine, but that, what is still more important, we can have high speed production, comparable to that at which high speed paper machines are run, while at the same time securing uniform rovings of excellent quality. In this connection, it is to be observed that the speed of the wet end of the machine can, as will be appreciated by those skilled in the art, without difficulty be made to run at as high as 500. or more feet per minute; andour invention makes possible the coordination of successful furllng or roving of pulp ribbons with such speed of manufacture.

It is most desirable that the furling roll have an effective operating surface of relatively large diameter. This feature was discovered only after experimentation and mathematical consideration of the forces which affect what wemay term the roving action. It has been established that the formula which governs the normal pressure between the drier felt and the drying cylinders of a paper machine is:

, per inch width of wire. Then,

2T 2 X 6 D p /4- Not at all obvious was the fact that the calculation did not require a consideration of the arc of contact between the roll and the wire i. e.,,the roving or operative area. It can, however, be shown by analytical geometry that this arc of contact has no effect upon the pressure. In accordance with our invention, therefore, we use a roving roll of an effective diameter of at least about 16 inches, although when the roll is covered with a resilient'or hi hly compressible material such as sponge ru her or its equivalent the actual diameter of the roll may be less than about 16 inches, because of the flattening or distortion at the area of contact with the wire and the attendant increase in the eifective diameter. Whether or not our hypotheses are correct, it is a fact that in actual practicethe use of a roving roll having an effective diameter of at least about 16 inches makes for uniform and eminently satisfactory results; and, although the use of a roll of materiall smaller efiective diameter may be made to yield good rovings, the largerroll appears to be more fool-proof and permits of the simplest arrangement of guide rolls and the like.

With these and other features and objects in view, our invention will now be described in con'unction with the accompanying drawin w erein igure 1 represents a side view, partly in section, of a machine embodying our invention.

Figure 2 is an elevation of the front end of the machine.

Figure 3 is a fra mentary sectional detail on the. line 33 of igure 1.

Figure! shows. diagrammatically a section through a modified form of furling roll.

As shown in Figure 1, the wet end of the machine may include a suction roll indicated generally by the numeral 1 and a pulp vat inicatedgenerally by the numeral 2. A wire cloth or screen .3,such as used on a Four drinier machine; asses tightly about the roll 1, which is provi edwith spaced, peripheral grooves (not shown), communicating with its interior so as to cause the deposition of pulp as spaced, continuous ribbons when an aqueous pulp sus v sion is run onto'the roll from the vat 2. e vat is made up of a bottom 4 and side walls 5 whose front edges termi-- nate in close proximity to the rolls so as to direct a flow of the pulp suspension onto the wire, the front edges 5a of the side walls being curved to conform to that portion of the roll periphery presented thereto. The roll proper 15 an ported at its ends in suitable hearing mom 6 and is rotated by suitable means (not shown), thereby serving to'drive the wire in. the direction indicated by arrows. The vat receives a supply of pulp suspension of suitable consistency from a pipe 7 entering the vat bottom 8 at a point somewhat removed from the rear wall 9. The pulp suspension flows under a bafile plate or false botwhich ribbons of pulp are deposited on the wire. In order that a uniformly textured deposit of pulp be made, an excess of highly dilute pulp suspension is delivered into the vat, the excess taking the course-indicated past the clearance or throat space 12 between the bafile and the roll, and thence over the bafiic and dam to the rear of the vat. The excess pulp suspension may leave the vat through a pipe 13 returning it to the source of supply (not shown). The clearance 12 between the bafile and roll maybe varied, as by constructing the baflle in two pieces, as shown, with the front piece 14 being longitudinally adjustable. The head of suspension in the vat may be controlled as by a vertically adjustable gate 15 arranged above the bafile 10 and immediately in front of the dam 11. 1 The adjustment may be made as by a hand-Wheel 16 outside of the vat and. fixed to a vertical screw shaft 17 engaging a pair of spaced nut elements 18 on the gate. The pulp suspension employed may be of a consistency of only about 1/40% or even less, in which case large quantities of water are removed during the formation of the pulp ribbons. To this end, a suction chamber 19 occupying a sector some what greater than the peripheral portion of the roll in contact with the pulp suspension flow, maybe arranged inside of the roll, so as to accelerate withdrawal of the water from the pulp and thus to promote the formation of pulp ribbons on the wire 3. The wire carrying the pulp ribbons out of the pulp suspension may then pass over a smaller second suction chamber 20 adjacent to the'chamber 19. In depositing on the wire, while the pulp fibers assume a preponderantly longitudinal lay, particularly when the wire is traveling at such speeds as 500 feet per minute, or (greater, a certain amount of cross-laying an random-laying of the fibers Inevita- .bly ensues, particularly on account of the tarbulence and cddying of the pulp suspension as it flows through the clearance 12 and the currents or water cascading into the roll.

The wire carrying deposits of pulp ribbons proceeds horizontally from the roll 1 over the desired number of suction house 21 maintained under suficient suction to dewater the rihbons to a water content of about 250% to 300%, more or less, based on the weight of amenable to ready furling' or rolling into rovings or round odies, but it is of course desired that the furling action be made positlve and uniform. To this end, the wire passes over a pressure box 22, whereinto a gaseous medium under pressure, such as compressed air, is delivered by a pipe 23 from a pump or pressure chamber (not shown). The compressed air is emitted from the box as best shown in Figure 3, through a series 0% apertures 24, arranged transversely of the top of the box and directly under the edge -portions on only one side of the ribbons.

Each air blast has the effect of progressively lifting the edge portion of a ribbon from the wire as the wire moves thereover without, however, weakening, rupturimgor dislodging the ribbons from their initial placement. In fact, the lifting i is only temporary and merely detaches the edge portions of the rib- .bons from the wire so that the initiation of the subsequent fur-ling or convoluting-action thereupon is rendered easy and positive. The wire then passes over the guide roll 240, whence it takes a vertically downward course to a spaced guide roll 25. The vertical wire stretch 3a between the rolls 24 and 25 is where the furling can be most conveniently accomplished. For this purpose, a turling dandy roll 26, whose peripher is covered with wire cloth of about 45 or ner mesh, is shown in engagement with the confronting zone or stretch 3a over an appreciable arc of contact, the axis of theroll cing inclined at an angle of, say, 80, more or less, to the direction of travelof'the wire and the ribbons supported thereon. The wire-cloth covering ma be fixed as by welding to a series of space( rings 27 constituting the rims of spiders 28 suitably anchored to the shaft 29 for the roll. The shaftiillustrated'is hollow and is provided with perforations-30 through its side walls to permit the passage therethrough of hot air or other heated gaseous medium which in flowing through the perforations and outthrough the wire-cloth covering dries the moist wirecloth before it* makes contact with thef'dainp; -ribbons on the traveling wire. other; t ng-means, 'such as electric units, may H ar n'fged inside of the roll to dry the roll per 1 and thereby to revent clingingof ons to the periphery. The mu."- ay be journaled for rotation in brackets 31 ex ending from atransv sebar 32 toward th wire 30.. As the puip-iribbons, indicated p by the numeral 331ini Ei'gure 2, enter the nip .definedby the wire 3o-"and fthe roll .26, the a relative angular movement between the wire and-theroll causes a furl outot-the ribbons int round form, with the ed pert qas' rrf mg 'or lateral rolling lydetached from the sygurling start, particuib us are pliable and of passing therethrou h and bein roll may be positively driven, although, as illustrated,the rotation of the roll is realized by frictional contact with the traveling wire.

he furling or roving action com' acts the pulp ribbons into uniform round bodies or strands 34, detached or readily detachable from .the wire as they issue from the nip. The strands may be collected continuously as by a pneumatic system, such as described and c aimed in application Serial No. 504,029, filed December 22, 1930, by Milton 0. Schur. After collection, the rovings may be twisted, plied into yarns or strings, and dried. Provision is preferably made to vary the angle of inclination of the furling roll 26, for which purpose the bar 32 may have a centrally located pivot pin 35, normally fixed at its outer threaded end by a nut 36 to the cross-member 37 of pair of spaced standards 38. If desired, bolts 39 positioned near the ends of the bar 32 may project through arcuate slots 40 in the cross-member 37, so as to permit firm fixture of the roll to the cross-member by nuts 41. In adjusting the angularity of the roll, the

three nuts are loosened, and, after the roll has been swiveled to the desired angularity,

thenuts are tighteneddown against the mem ber 37. In returning to the suction roll 1 from the roll 25, the wire takes'an inclined upward course over a tightening roll 42,and'

then runs substantially horizontally over a guide roll 43 to thesuction roll. The tightenmg means for the roll 42 may, for instance,

comprisea hand-wheel 44 on a shaft 45 to which is fixed a pair of bevel gears 46, each of which meshes with a bevel gear 47 on one end of a horizontsil screw shaft 48. Each screw shaft is in threaded engagement with a movable standard or support 49 for the roll, journaled and fixed at its ot er end to tie machine frame .50. By turning the hand-wheel in the proper direction, the roll 42 ma be made to move horizontally against the wire to take up such slack as may exist therein at any time.

It is, of course, desirable to wash the wire free from residual fibers as by spraying water thereonto from a manifold'51 arranged transversely above the wire, near the roll 42 or at any other suitable location. So, too, the suction roll 1 preferably undergoes the action of water'issuing from a manifold 52 arranged inside the roll near its periphery,-

so that residual fibers are cleared therefrom before it reaches the pulp-depositing station.

Rather than using a hard-surfaced dandy roll or other friction roll of a diameter of at least about 16 inches for the furlin'g operation, as indicated in Figure 4, a much smaller roll 53 may be used when'the periphery 54 is made of sponge rubber or other compressible or resilient material which, in bearing a ainst. the wire 3a, becomesso flattened or distorted atits region of contact 54a with the lee wire as to constitute in effect the periphery of a roll of about 16 inches or greater diameter, as illustrated in dotted outline.

Employing the method and machine of the present invention, the ribbons of pulp are furled or roved directly on the formlng wire, wherefore there is little liability to damage or destroy the uniformity of texture or formation previously realized at the wet end of the machine. Again, by detaching the edge portions on only one side of the ribbons and by using a furling roll whose periphery is preferably made of wire cloth, there is little, if any, danger of intermingling the ribbons during furling or roving, even whenthey are as closely spaced as to inches apart; and the rovings separate from the wire quite readily. The furling action is positive and uniform, by which we mean that there is no tendency to miss catching or engaging the detached edge portions and convoluting them into round bodies or strands entirely free from raggedness or lines of cleavage in its structure.- The pulp ribbons are compacted during roving, but with no danger of breaking them. Some water is re moved during roving, the pulp ribbons hav-' ing a water content of, say, about 300%, based on fiber, before roving."

By arranging the axis of the furling and compacting roll at an angle of 80, more or less, to the longitudinal path of movement of the wire but in parallelism with the surface of the wire. the movement of the periphery of the roll ismainly in the direction of the movement of the wire, buthas a'lateral component sulficient to effect the desired furling or rolling out of the ribbons without, however, causing their in'termingling or snarling. The are of engagement between the roll and the wire should be appreciable, as shown, and may, of course, be varied by adjusting the tension in the wire and consequently the amount of give or inward bulging of the wire at its roll-engaging or operative portion, in the case of the resilient roll shown in Fig. 4. In the case of the non-resilient roll 28, shown in Fig. 1, the increased arc of Contact is obtained by loosening the carrying wire and by pushing theroll 28 inwardly against the wire. The furling of the ribbons on the forming wire can-be accomplished at high. speeds and while they are quite damp,conditions under which it would be exceedingly difficult to operate without breakage and othertroubles if the ribbons were stripped from the wire and transported through an atmospheric gap to-furling mechanism such asbelts. Despite the. fact that the edge portions on one side of the ribbons I are detached from the forming wire to facilitate initiation of their furling and compacting, nevertheless they are maintained against misplacement by those fibers on their opposite edge portions still in entanglement means shown and described, including the Y assembly of the forming wire, suction roll,

and vat, has been found to give excellent results in actual practice, but, inasmuch as it is the invention of Roy E. Brawn and has been described and claimed in application Serial No. 542,610, filed June 6, 1931, we make-no claim herein thereto, except in so far as it constitutes broadly an element of our invention. Broadly speaking, we employ a circuitously-traveling wire cloth made up essentially of two horizontal stretches and a vertical stretch at one end at which furling of the pulp ribbons is accomplished after the ribbons have been suitably formed from aqueous suspension at the other end and have undergone partial dewatering on their way to the vertical stretch. While it is nreferable to lift only the edge portions of the pulp ribbons from the forming wire before roving, the entire ribbons may be detached as with an air shower. When the ribbon is furled on the forming wire, it is important to detach at least an edge in order to permit free roving. This latter combination of detaching the ribbons as a whole from the wire and then roving the detached ribbons on the wire by means of a furling roll is the practice which we inaugurated before the advent .of the improved method of lifting only one edge. As already indicated, although the roving roll may be independently driven, we prefer to have it rotated through contact with the wire, for the reason that,

unless the roll is driven at exactly the right speed, the rovings are damaged. When a properly balanced roll ismounted in good bearings, there is no ditiiculty in driving it by means of the wire in spite of the fact that the axis of the roving roll is not at right angles to the direction of travel of the wire. This is an important feature, for it was only through actual trial that we established the fact that it was possible to drive the inclined roll without getting into trouble. On the other hand, the driving of the roll independently requires a finely adjustable variable speed drive; and a roll independently driven is always a potential sourceof considerable trouble.

- What'we claim is:

1. The combination with a travelin carrier for ribbons of damp, interfelted brous material, of a roll frictionally en agin said carrier to define a ni into whic sai ribbons may pass, the axls of said roll being arranged at an angle of inclination to the direction of travel of said carrier.

2. The combination with a foraminous traveling carrier and means for depositing ribbons of pulp on said carrier, of a roll frictionally engaging said carrier to define a nip into which said ribbons may pass, the axis of said roll'being arranged at an an is of inclination to the direction of travel oi said carrier.

3. The combination with a traveling wire cloth and means for depositing ribbons of pulp on said cloth, of a wire-cloth-peripheried roll frictionally engaging said traveling cloth and ribbons and arranged at an angle of inclination to the direction of travel of said carrier.

4. The combination with a travelintfi) carrier for ribbons of damp, inter-felted rous material, of a roll frictionally engpgin said carrier to define a nip into whic sai ribbons may pass, the axls of said roll being arranged at an angle of inclination to the rection of travel of said carrier and said rollbeing mounted so, as to be rotated by said carrier. 5. The combination with a travelin wire cloth for ribbons of damp, interfelted brous material, of a wire-cloth-peripheried roll frictionally engaging said carrier and ribbons and arranged at an angle of inclination to the direction of travel of said carrier said roll being mounted so as to be'rotated by said wire cloth. 6. The combination with a travelinhgb carrier for ribbons'of damp, inter-felted rous material, of a roll frictionally engaging said carrier and ribbons and arranged at an angle of inclination to the direction of travel of said carrier, said roll being surfaced with a resilient material and flattened out at its vcarrier-engaging portion to constitute a roll having an eflective diameter larger than when unfia-ttened.

7. The combination with a traveling wire cloth, means for depositing from aqueous suspension ribbons of wet pulp on said cloth,

and means for partially dewatering said ribbons on said cloth, of a wire-clotbperipheried 'roll frietionally engaging said cloth and ribbons and arranged at an angl of inclination to thedirection of travel of said wire, and means for drying the periphery of said roll after it moves out of engagement with said damp ribbons. a 1

' 8. The combination with a traveling wire cloth and means for depositing from aqueous suspension ribbons of wet pulp on said cloth,

of a wire-cloth-peripheried roll frictionally engaging said cloth and ribbons and arran d at .an angle of inclination to the direction of travel of said wire, and means for adjusting the angularity of said roll.

9. The combination with a circuitously traveling'wire'eloth,made up essentially of two horizontal stretches and a vertical-stretch at one end, means for depositing ribbons of pulp'from aqueous suspension on'said cloth at saidother end, andmeans for partially de watering the ribbons beforethey reach the vertical stretch, of a wire-eloth-peripheried roll frictionally engaging said j vertical stretch of cloth and ribbons and arran ed at an angle of inclination to the direct on of: travel of'saidwire.

10. The combination with a traveling carrier for ribbons, of damp, interfelted fibrous material, of a roll having a diameter of at least about 16 -inches,'frictionally engaging said carrier to define a nip into which said ribbons may1pass,the axis of said roll being arran ed'at an angle of inclination to the direction of travel of said carrier.

11. The combination with a traveling wire cloth and means for depositing ribbons of pulp on said cloth, of .a wire-cloth-peripheried roll having a diameter of at least about 16 inches engaging said traveling cloth and ribbons and arranged at an angle of inclination to the direction of travel of said carrier. 12.- A method which comprises progressively depositing from aqueous suspension pulp fibers as ribbons on a traveling foraminouscarrier,and, while on the cairier, leading said ribbons into a .nip by way of a tapered ingress defined by said carrier and a r angle to the direction of travel of said carrier, thereby frictionally engaging the edge portions of said ribbons and into round form.

'13. A method which comprises progressively depositin from aqueous suspension pulp fibers as r1 bons on a traveling wire cloth, and, while on the cloth, leading said ribbons into a nip by way of a ta ered in-. gress defined by said wirecloth an another wire cloth movin'g continuously into contact with said first-mentioned wire cloth in a curved path and at an angle to the direction of travel of said first-mentioned wire cloth, thereby fric'tionally enga 'ng the edge portions of said ribbons an rolling them out into round form.

polling them out 14. A method which comprises progrescurved path at an angle to thedirection of 1 travel of said carrier and whose arc of curva ture in contact with said carrier. corresponds to that of a roll havin a diameter of at least about 16 inches,there y frictionally engaging the edge portions of said ribbons and r0 1i i ng them outinto round form. 15. A method which comprises depositing from-aqueous suspension ulp fibers as ribbonson a travelingwire 0 0th and, while on the cloth, leading said ribbons into a nip by way of a tapered ingress defined by said wire cloth and another Wire cloth moving continuously into contact with said first-mew tioned wire cloth in a curved path and at an angle to the direction of travel of said firstmentioned wire cloth and whose arc of curvature in contact with said first-mentioned wire cloth corresponds to that of a roll havin a 9 diameter of'at least about 16 inches, there y frictionally. engaging the edge portions of ;aid ribbons and rolling them out into round orm.

In testimony whereof we have afiixed our signatures. v

MILTON Q SCHUR. WILLIAM B. MEGLITZ. 

